mm: convert return type of handle_mm_fault() caller to vm_fault_t

Use new return type vm_fault_t for fault handler.  For now, this is just
documenting that the function returns a VM_FAULT value rather than an
errno.  Once all instances are converted, vm_fault_t will become a
distinct type.

Ref-> commit 1c8f4220 ("mm: change return type to vm_fault_t")

In this patch all the caller of handle_mm_fault() are changed to return
vm_fault_t type.

Link: http://lkml.kernel.org/r/20180617084810.GA6730@jordon-HP-15-Notebook-PCSigned-off-by: Souptick Joarder <jrdr.linux@gmail.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Richard Kuo <rkuo@codeaurora.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Michal Simek <monstr@monstr.eu>
Cc: James Hogan <jhogan@kernel.org>
Cc: Ley Foon Tan <lftan@altera.com>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: James E.J. Bottomley <jejb@parisc-linux.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Palmer Dabbelt <palmer@sifive.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: David S. Miller <davem@davemloft.net>
Cc: Richard Weinberger <richard@nod.at>
Cc: Guan Xuetao <gxt@pku.edu.cn>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: "Levin, Alexander (Sasha Levin)" <alexander.levin@verizon.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

arch/alpha/mm/fault.c

@@ -87,7 +87,8 @@ do_page_fault(unsigned long address, unsigned long mmcsr,
 	struct vm_area_struct * vma;
 	struct mm_struct *mm = current->mm;
 	const struct exception_table_entry *fixup;
-	int fault, si_code = SEGV_MAPERR;
+	int si_code = SEGV_MAPERR;
+	vm_fault_t fault;
 	unsigned int flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE;
 
 	/* As of EV6, a load into $31/$f31 is a prefetch, and never faults

arch/arc/mm/fault.c

@@ -15,6 +15,7 @@
 #include <linux/uaccess.h>
 #include <linux/kdebug.h>
 #include <linux/perf_event.h>
+#include <linux/mm_types.h>
 #include <asm/pgalloc.h>
 #include <asm/mmu.h>
 
@@ -66,7 +67,8 @@ void do_page_fault(unsigned long address, struct pt_regs *regs)
 	struct task_struct *tsk = current;
 	struct mm_struct *mm = tsk->mm;
 	siginfo_t info;
-	int fault, ret;
+	int ret;
+	vm_fault_t fault;
 	int write = regs->ecr_cause & ECR_C_PROTV_STORE;  /* ST/EX */
 	unsigned int flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE;
 

arch/arm/mm/fault.c

@@ -224,12 +224,12 @@ static inline bool access_error(unsigned int fsr, struct vm_area_struct *vma)
 	return vma->vm_flags & mask ? false : true;
 }
 
-static int __kprobes
+static vm_fault_t __kprobes
 __do_page_fault(struct mm_struct *mm, unsigned long addr, unsigned int fsr,
 		unsigned int flags, struct task_struct *tsk)
 {
 	struct vm_area_struct *vma;
-	int fault;
+	vm_fault_t fault;
 
 	vma = find_vma(mm, addr);
 	fault = VM_FAULT_BADMAP;
@@ -264,7 +264,8 @@ do_page_fault(unsigned long addr, unsigned int fsr, struct pt_regs *regs)
 {
 	struct task_struct *tsk;
 	struct mm_struct *mm;
-	int fault, sig, code;
+	int sig, code;
+	vm_fault_t fault;
 	unsigned int flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE;
 
 	if (notify_page_fault(regs, fsr))

arch/arm64/mm/fault.c

@@ -379,12 +379,12 @@ static void do_bad_area(unsigned long addr, unsigned int esr, struct pt_regs *re
 #define VM_FAULT_BADMAP		0x010000
 #define VM_FAULT_BADACCESS	0x020000
 
-static int __do_page_fault(struct mm_struct *mm, unsigned long addr,
+static vm_fault_t __do_page_fault(struct mm_struct *mm, unsigned long addr,
 			   unsigned int mm_flags, unsigned long vm_flags,
 			   struct task_struct *tsk)
 {
 	struct vm_area_struct *vma;
-	int fault;
+	vm_fault_t fault;
 
 	vma = find_vma(mm, addr);
 	fault = VM_FAULT_BADMAP;
@@ -427,7 +427,7 @@ static int __kprobes do_page_fault(unsigned long addr, unsigned int esr,
 	struct task_struct *tsk;
 	struct mm_struct *mm;
 	struct siginfo si;
-	int fault, major = 0;
+	vm_fault_t fault, major = 0;
 	unsigned long vm_flags = VM_READ | VM_WRITE;
 	unsigned int mm_flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE;
 

arch/hexagon/mm/vm_fault.c

@@ -52,7 +52,7 @@ void do_page_fault(unsigned long address, long cause, struct pt_regs *regs)
 	struct mm_struct *mm = current->mm;
 	int si_signo;
 	int si_code = SEGV_MAPERR;
-	int fault;
+	vm_fault_t fault;
 	const struct exception_table_entry *fixup;
 	unsigned int flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE;
 

arch/ia64/mm/fault.c

@@ -86,7 +86,7 @@ ia64_do_page_fault (unsigned long address, unsigned long isr, struct pt_regs *re
 	struct vm_area_struct *vma, *prev_vma;
 	struct mm_struct *mm = current->mm;
 	unsigned long mask;
-	int fault;
+	vm_fault_t fault;
 	unsigned int flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE;
 
 	mask = ((((isr >> IA64_ISR_X_BIT) & 1UL) << VM_EXEC_BIT)

arch/m68k/mm/fault.c

@@ -70,7 +70,7 @@ int do_page_fault(struct pt_regs *regs, unsigned long address,
 {
 	struct mm_struct *mm = current->mm;
 	struct vm_area_struct * vma;
-	int fault;
+	vm_fault_t fault;
 	unsigned int flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE;
 
 	pr_debug("do page fault:\nregs->sr=%#x, regs->pc=%#lx, address=%#lx, %ld, %p\n",
@@ -136,7 +136,7 @@ int do_page_fault(struct pt_regs *regs, unsigned long address,
 	 */
 
 	fault = handle_mm_fault(vma, address, flags);
-	pr_debug("handle_mm_fault returns %d\n", fault);
+	pr_debug("handle_mm_fault returns %x\n", fault);
 
 	if ((fault & VM_FAULT_RETRY) && fatal_signal_pending(current))
 		return 0;

arch/microblaze/mm/fault.c

@@ -90,7 +90,7 @@ void do_page_fault(struct pt_regs *regs, unsigned long address,
 	struct mm_struct *mm = current->mm;
 	int code = SEGV_MAPERR;
 	int is_write = error_code & ESR_S;
-	int fault;
+	vm_fault_t fault;
 	unsigned int flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE;
 
 	regs->ear = address;

arch/mips/mm/fault.c

@@ -43,7 +43,7 @@ static void __kprobes __do_page_fault(struct pt_regs *regs, unsigned long write,
 	struct mm_struct *mm = tsk->mm;
 	const int field = sizeof(unsigned long) * 2;
 	int si_code;
-	int fault;
+	vm_fault_t fault;
 	unsigned int flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE;
 
 	static DEFINE_RATELIMIT_STATE(ratelimit_state, 5 * HZ, 10);

arch/nds32/mm/fault.c

@@ -73,7 +73,7 @@ void do_page_fault(unsigned long entry, unsigned long addr,
 	struct mm_struct *mm;
 	struct vm_area_struct *vma;
 	int si_code;
-	int fault;
+	vm_fault_t fault;
 	unsigned int mask = VM_READ | VM_WRITE | VM_EXEC;
 	unsigned int flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE;
 

arch/nios2/mm/fault.c

@@ -47,7 +47,7 @@ asmlinkage void do_page_fault(struct pt_regs *regs, unsigned long cause,
 	struct task_struct *tsk = current;
 	struct mm_struct *mm = tsk->mm;
 	int code = SEGV_MAPERR;
-	int fault;
+	vm_fault_t fault;
 	unsigned int flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE;
 
 	cause >>= 2;

arch/openrisc/mm/fault.c

@@ -53,7 +53,7 @@ asmlinkage void do_page_fault(struct pt_regs *regs, unsigned long address,
 	struct mm_struct *mm;
 	struct vm_area_struct *vma;
 	int si_code;
-	int fault;
+	vm_fault_t fault;
 	unsigned int flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE;
 
 	tsk = current;

arch/parisc/mm/fault.c

@@ -262,7 +262,7 @@ void do_page_fault(struct pt_regs *regs, unsigned long code,
 	struct task_struct *tsk;
 	struct mm_struct *mm;
 	unsigned long acc_type;
-	int fault = 0;
+	vm_fault_t fault = 0;
 	unsigned int flags;
 
 	if (faulthandler_disabled())

arch/powerpc/include/asm/copro.h

@@ -10,13 +10,15 @@
 #ifndef _ASM_POWERPC_COPRO_H
 #define _ASM_POWERPC_COPRO_H
 
+#include <linux/mm_types.h>
+
 struct copro_slb
 {
 	u64 esid, vsid;
 };
 
 int copro_handle_mm_fault(struct mm_struct *mm, unsigned long ea,
-			  unsigned long dsisr, unsigned *flt);
+			  unsigned long dsisr, vm_fault_t *flt);
 
 int copro_calculate_slb(struct mm_struct *mm, u64 ea, struct copro_slb *slb);
 

arch/powerpc/mm/copro_fault.c

@@ -34,7 +34,7 @@
  * to handle fortunately.
  */
 int copro_handle_mm_fault(struct mm_struct *mm, unsigned long ea,
-		unsigned long dsisr, unsigned *flt)
+		unsigned long dsisr, vm_fault_t *flt)
 {
 	struct vm_area_struct *vma;
 	unsigned long is_write;

arch/powerpc/mm/fault.c

@@ -156,7 +156,7 @@ static noinline int bad_access(struct pt_regs *regs, unsigned long address)
 }
 
 static int do_sigbus(struct pt_regs *regs, unsigned long address,
-		     unsigned int fault)
+		     vm_fault_t fault)
 {
 	siginfo_t info;
 	unsigned int lsb = 0;
@@ -187,7 +187,8 @@ static int do_sigbus(struct pt_regs *regs, unsigned long address,
 	return 0;
 }
 
-static int mm_fault_error(struct pt_regs *regs, unsigned long addr, int fault)
+static int mm_fault_error(struct pt_regs *regs, unsigned long addr,
+				vm_fault_t fault)
 {
 	/*
 	 * Kernel page fault interrupted by SIGKILL. We have no reason to
@@ -415,7 +416,7 @@ static int __do_page_fault(struct pt_regs *regs, unsigned long address,
  	int is_exec = TRAP(regs) == 0x400;
 	int is_user = user_mode(regs);
 	int is_write = page_fault_is_write(error_code);
-	int fault, major = 0;
+	vm_fault_t fault, major = 0;
 	bool must_retry = false;
 
 	if (notify_page_fault(regs))

arch/powerpc/platforms/cell/spufs/fault.c

@@ -111,7 +111,7 @@ int spufs_handle_class1(struct spu_context *ctx)
 {
 	u64 ea, dsisr, access;
 	unsigned long flags;
-	unsigned flt = 0;
+	vm_fault_t flt = 0;
 	int ret;
 
 	/*

arch/riscv/mm/fault.c

@@ -41,7 +41,8 @@ asmlinkage void do_page_fault(struct pt_regs *regs)
 	struct mm_struct *mm;
 	unsigned long addr, cause;
 	unsigned int flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE;
-	int fault, code = SEGV_MAPERR;
+	int code = SEGV_MAPERR;
+	vm_fault_t fault;
 
 	cause = regs->scause;
 	addr = regs->sbadaddr;

arch/s390/mm/fault.c

@@ -341,7 +341,8 @@ static noinline int signal_return(struct pt_regs *regs)
 	return -EACCES;
 }
 
-static noinline void do_fault_error(struct pt_regs *regs, int access, int fault)
+static noinline void do_fault_error(struct pt_regs *regs, int access,
+					vm_fault_t fault)
 {
 	int si_code;
 
@@ -401,7 +402,7 @@ static noinline void do_fault_error(struct pt_regs *regs, int access, int fault)
  *   11       Page translation     ->  Not present       (nullification)
  *   3b       Region third trans.  ->  Not present       (nullification)
  */
-static inline int do_exception(struct pt_regs *regs, int access)
+static inline vm_fault_t do_exception(struct pt_regs *regs, int access)
 {
 	struct gmap *gmap;
 	struct task_struct *tsk;
@@ -411,7 +412,7 @@ static inline int do_exception(struct pt_regs *regs, int access)
 	unsigned long trans_exc_code;
 	unsigned long address;
 	unsigned int flags;
-	int fault;
+	vm_fault_t fault;
 
 	tsk = current;
 	/*
@@ -564,7 +565,8 @@ static inline int do_exception(struct pt_regs *regs, int access)
 void do_protection_exception(struct pt_regs *regs)
 {
 	unsigned long trans_exc_code;
-	int access, fault;
+	int access;
+	vm_fault_t fault;
 
 	trans_exc_code = regs->int_parm_long;
 	/*
@@ -599,7 +601,8 @@ NOKPROBE_SYMBOL(do_protection_exception);
 
 void do_dat_exception(struct pt_regs *regs)
 {
-	int access, fault;
+	int access;
+	vm_fault_t fault;
 
 	access = VM_READ | VM_EXEC | VM_WRITE;
 	fault = do_exception(regs, access);

arch/sh/mm/fault.c

@@ -313,7 +313,7 @@ do_sigbus(struct pt_regs *regs, unsigned long error_code, unsigned long address)
 
 static noinline int
 mm_fault_error(struct pt_regs *regs, unsigned long error_code,
-	       unsigned long address, unsigned int fault)
+	       unsigned long address, vm_fault_t fault)
 {
 	/*
 	 * Pagefault was interrupted by SIGKILL. We have no reason to
@@ -396,7 +396,7 @@ asmlinkage void __kprobes do_page_fault(struct pt_regs *regs,
 	struct task_struct *tsk;
 	struct mm_struct *mm;
 	struct vm_area_struct * vma;
-	int fault;
+	vm_fault_t fault;
 	unsigned int flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE;
 
 	tsk = current;

arch/sparc/mm/fault_32.c

@@ -166,7 +166,8 @@ asmlinkage void do_sparc_fault(struct pt_regs *regs, int text_fault, int write,
 	unsigned int fixup;
 	unsigned long g2;
 	int from_user = !(regs->psr & PSR_PS);
-	int fault, code;
+	int code;
+	vm_fault_t fault;
 	unsigned int flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE;
 
 	if (text_fault)

arch/sparc/mm/fault_64.c

@@ -278,7 +278,8 @@ asmlinkage void __kprobes do_sparc64_fault(struct pt_regs *regs)
 	struct mm_struct *mm = current->mm;
 	struct vm_area_struct *vma;
 	unsigned int insn = 0;
-	int si_code, fault_code, fault;
+	int si_code, fault_code;
+	vm_fault_t fault;
 	unsigned long address, mm_rss;
 	unsigned int flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE;
 

arch/um/kernel/trap.c

@@ -72,7 +72,7 @@ int handle_page_fault(unsigned long address, unsigned long ip,
 	}
 
 	do {
-		int fault;
+		vm_fault_t fault;
 
 		fault = handle_mm_fault(vma, address, flags);
 

arch/unicore32/mm/fault.c

@@ -168,11 +168,11 @@ static inline bool access_error(unsigned int fsr, struct vm_area_struct *vma)
 	return vma->vm_flags & mask ? false : true;
 }
 
-static int __do_pf(struct mm_struct *mm, unsigned long addr, unsigned int fsr,
-		unsigned int flags, struct task_struct *tsk)
+static vm_fault_t __do_pf(struct mm_struct *mm, unsigned long addr,
+		unsigned int fsr, unsigned int flags, struct task_struct *tsk)
 {
 	struct vm_area_struct *vma;
-	int fault;
+	vm_fault_t fault;
 
 	vma = find_vma(mm, addr);
 	fault = VM_FAULT_BADMAP;
@@ -209,7 +209,8 @@ static int do_pf(unsigned long addr, unsigned int fsr, struct pt_regs *regs)
 {
 	struct task_struct *tsk;
 	struct mm_struct *mm;
-	int fault, sig, code;
+	int sig, code;
+	vm_fault_t fault;
 	unsigned int flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE;
 
 	tsk = current;

arch/x86/mm/fault.c

@@ -16,6 +16,7 @@
 #include <linux/prefetch.h>		/* prefetchw			*/
 #include <linux/context_tracking.h>	/* exception_enter(), ...	*/
 #include <linux/uaccess.h>		/* faulthandler_disabled()	*/
+#include <linux/mm_types.h>
 
 #include <asm/cpufeature.h>		/* boot_cpu_has, ...		*/
 #include <asm/traps.h>			/* dotraplinkage, ...		*/
@@ -999,7 +1000,7 @@ do_sigbus(struct pt_regs *regs, unsigned long error_code, unsigned long address,
 
 static noinline void
 mm_fault_error(struct pt_regs *regs, unsigned long error_code,
-	       unsigned long address, u32 *pkey, unsigned int fault)
+	       unsigned long address, u32 *pkey, vm_fault_t fault)
 {
 	if (fatal_signal_pending(current) && !(error_code & X86_PF_USER)) {
 		no_context(regs, error_code, address, 0, 0);
@@ -1213,7 +1214,7 @@ __do_page_fault(struct pt_regs *regs, unsigned long error_code,
 	struct vm_area_struct *vma;
 	struct task_struct *tsk;
 	struct mm_struct *mm;
-	int fault, major = 0;
+	vm_fault_t fault, major = 0;
 	unsigned int flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE;
 	u32 pkey;
 

arch/xtensa/mm/fault.c

@@ -42,7 +42,7 @@ void do_page_fault(struct pt_regs *regs)
 	int code;
 
 	int is_write, is_exec;
-	int fault;
+	vm_fault_t fault;
 	unsigned int flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE;
 
 	code = SEGV_MAPERR;

drivers/iommu/amd_iommu_v2.c

@@ -508,7 +508,7 @@ static void do_fault(struct work_struct *work)
 {
 	struct fault *fault = container_of(work, struct fault, work);
 	struct vm_area_struct *vma;
-	int ret = VM_FAULT_ERROR;
+	vm_fault_t ret = VM_FAULT_ERROR;
 	unsigned int flags = 0;
 	struct mm_struct *mm;
 	u64 address;

drivers/iommu/intel-svm.c

@@ -24,6 +24,7 @@
 #include <linux/pci-ats.h>
 #include <linux/dmar.h>
 #include <linux/interrupt.h>
+#include <linux/mm_types.h>
 #include <asm/page.h>
 
 #define PASID_ENTRY_P		BIT_ULL(0)
@@ -594,7 +595,8 @@ static irqreturn_t prq_event_thread(int irq, void *d)
 		struct vm_area_struct *vma;
 		struct page_req_dsc *req;
 		struct qi_desc resp;
-		int ret, result;
+		int result;
+		vm_fault_t ret;
 		u64 address;
 
 		handled = 1;

drivers/misc/cxl/fault.c

@@ -134,7 +134,7 @@ static int cxl_handle_segment_miss(struct cxl_context *ctx,
 
 int cxl_handle_mm_fault(struct mm_struct *mm, u64 dsisr, u64 dar)
 {
-	unsigned flt = 0;
+	vm_fault_t flt = 0;
 	int result;
 	unsigned long access, flags, inv_flags = 0;
 

drivers/misc/ocxl/link.c

@@ -2,6 +2,7 @@
 // Copyright 2017 IBM Corp.
 #include <linux/sched/mm.h>
 #include <linux/mutex.h>
+#include <linux/mm_types.h>
 #include <linux/mmu_context.h>
 #include <asm/copro.h>
 #include <asm/pnv-ocxl.h>
@@ -126,7 +127,7 @@ static void ack_irq(struct spa *spa, enum xsl_response r)
 
 static void xsl_fault_handler_bh(struct work_struct *fault_work)
 {
-	unsigned int flt = 0;
+	vm_fault_t flt = 0;
 	unsigned long access, flags, inv_flags = 0;
 	enum xsl_response r;
 	struct xsl_fault *fault = container_of(fault_work, struct xsl_fault,

mm/hmm.c

@@ -299,14 +299,14 @@ static int hmm_vma_do_fault(struct mm_walk *walk, unsigned long addr,
 	struct hmm_vma_walk *hmm_vma_walk = walk->private;
 	struct hmm_range *range = hmm_vma_walk->range;
 	struct vm_area_struct *vma = walk->vma;
-	int r;
+	vm_fault_t ret;
 
 	flags |= hmm_vma_walk->block ? 0 : FAULT_FLAG_ALLOW_RETRY;
 	flags |= write_fault ? FAULT_FLAG_WRITE : 0;
-	r = handle_mm_fault(vma, addr, flags);
-	if (r & VM_FAULT_RETRY)
+	ret = handle_mm_fault(vma, addr, flags);
+	if (ret & VM_FAULT_RETRY)
 		return -EBUSY;
-	if (r & VM_FAULT_ERROR) {
+	if (ret & VM_FAULT_ERROR) {
 		*pfn = range->values[HMM_PFN_ERROR];
 		return -EFAULT;
 	}

mm/ksm.c

@@ -470,7 +470,7 @@ static inline bool ksm_test_exit(struct mm_struct *mm)
 static int break_ksm(struct vm_area_struct *vma, unsigned long addr)
 {
 	struct page *page;
-	int ret = 0;
+	vm_fault_t ret = 0;
 
 	do {
 		cond_resched();